Context:
Article in the Hindu – India is running out of phosphorus. Does the solution lie in our sewage?
About Phosphorus:
- Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus.
- Because it is highly reactive, phosphorus is never found as a free element on Earth.
- An essential mineral
- Naturally present in many foods and available as a dietary supplement.
Importance of phosphorus for health:
- A component of bones, teeth, DNA, RNA, cell membrane (phospholipids), ATP (body’s key energy source), etc.
- Phosphorus plays key roles in regulation of gene transcription, activation of enzymes, maintenance of normal pH in extracellular fluid, and intracellular energy storage.
Geopolitics of phosphorus:
- The world’s largest reserves – Morocco and the Western Sahara region
- But here, phosphorus coexists with cadmium, a heavy metal that can accumulate in animal and human kidneys when ingested.
- Removing cadmium is an expensive process.
- As a result, cadmium-laden fertilisers are often applied to the soil, absorbed by crops, and consumed, bioaccumulating in our bodies.
- Studies have found that this accelerates heart disease.
- India – world’s largest importer of phosphorus (most of it from the cadmium-laden deposits of West Africa).
Phosphorus and Sri Lanka political crisis:
Six nations possess significant cadmium-free phosphorus reserves. China imposed export restrictions in 2020, and several European Union countries discontinued their purchases from Russia. Consequently, the demand for safe phosphorus has surged. This is one of the factors that led Sri Lanka to prohibit synthetic fertilizer imports and transition to organic farming in 2021, which subsequently resulted in a sharp decline in crop yields, triggering a political crisis.
Phosphorus disposal problem:
- Only about a fifth of the phosphorus mined is actually consumed through food. Much of it is lost directly to water bodies as agricultural run-off, due to the excessive application of fertilisers.
- pollutes the environment – causes eutrophication
- Most of the phosphorus that people consume ends up in the sewage.
Sludge Mining:
- Sludge treatment processes are often the most difficult and costliest part of sewage treatment.
- Sludge stabilization processes reduce odours, pathogens, and biodegradable toxins, as well as bind heavy metals to inert solids, such as lime that will not leach into the groundwater.
- In the context of phosphorus availability in fertilizers and water pollution, there is potential for a game-changing innovation called sludge-mining. Companies like EasyMining in Europe are retrofitting sewage treatment plants to recover nutrients from the sewage.
Source: The Hindu
Previous year question
Recently, there has been a concern over the short supply of a group of elements called ‘rare earth metals’. Why?
1. China, which is the largest producer of these elements, has imposed some restrictions on their export.
2. Other than China, Australia, Canada and Chile, these elements are not found in any country.
3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements.
Which of the statement(s) given above is/are correct?
[UPSC Civil Services Exam – 2012 Prelims]
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (c)
